If you're dumb like me and don't realize what's going on at first: the source clip was of some guys talking about a game being shown on a video monitor at an angle. But he just wanted to see the game, not the guys. So he extracted the video and made it fullscreen. He did it by writing a script to turn every frame into a PNG, run them through an image-processing tool, then recompress a new video. Thankfully the monitor did not move much so some fixed distortion parameters worked.
Thankfully the monitor did not move much so some fixed distortion parameters worked.
Even if the monitor moved alot (http://hyperboleandahalf.blogspot.com/2010/04/alot-is-better...) it'd be fairly easy to write an algorithm to detect the four corners of the video. You basically want to throw some edge detection at it, and then look for anything that seem like corners.
> You basically want to throw some edge detection at it, and then look for anything that seem like corners.
Which, if you're a web dev like I am, seems scary at first, especially when you're (like me) lacking a CS education. However, as it turns out, understanding edge detection and Haar cascades (for feature detection, that was the problem I was solving) enough to be dangerous with OpenCV is surprisingly easy! I recently built some facial feature detection stuff in it that is in production right now, and it only took me a couple weeks :) So, have a play!
